of it itself. what it does do, it allows the city to commission an $8 million study to say, if we drain this, can we restore the area and find other ways to bring in power and water to the city? shorters like mike marshall say it's time to modernize our water system. >> this is one of nine storage facilities where we store our water. down below here, the river still flows and it will continue to flow once we restore the hetch hetchy valley. >> reporter: politically it's like touching the third rail. >> it is universal. there is not a single elected official in northern california that i'm aware of who is supporting prop f. >> you've been saying this measure f, it's insane, stupid. do you still stand by that today? >> oh, absolutely. when anybody rational looks at it, there is no answer to the cleanest water that this whole state if not the country has with our hetch hetchy water. >> reporter: and while only san francisco residents will vote on this study, it has much broader implications. there are 30 municipalities in the bay area that use water from hetch hetchy, including cities in san m